Yes, listen to Jeff Marchi in particular as he's extremely knowledgeable.
I think you're jumping to conclusions about "not being able to function sexually again".
I had my RP "robotically" five months ago, and while my sexual functioning is not fully there yet--climacturia is my main problem--it is progressing and I'm still at a comparatively early stage. It's expected to take a good year for full functioning to return. I'm a decade and half your senior, and nerve sparing was indeed accomplished.
I could have opted for radiation for the same effectiveness, apparently, but was leery of all its side effects, plus didn't like the possibility of long-term effects, as opposed to immediate ones that would gradually improve.
I'm pleased that my cancer seems to have been completely removed along with the organ, as you certainly don't want any metastasis!